Starting off as a young noble on a quest for revenge, Ezio is introduced to the order of Assassins, where he slowly learns to overcome his anger and embrace the order's teachings. Rising to the rank of Grand Master in his later years, Ezio breaks the Templar's dominance in Italy and restores the order's power, also doing so in Spain, Turkey, and indirectly, China and most of Europe. The character as such, his depiction, personality and development, as well as the chronicling of his entire life have received critical acclaim.

As it is shown in the beginning of Assassin's Creed II, Ezio was born into the nobility on June 24, 1459, in Italian city of Florence. Ezio led an affluent, care-free lifestyle until a tragic turn of events changed his life forever. Betrayed by Uberto Alberti, who was a friend of his father, and other corrupt nobles, Ezio's family were the victims of an evil plot that ultimately took the lives of his father,Giovanni, and two brothers. Of the Auditore men, only Ezio was able to escape because the capturing happened while Ezio was running errands for his father. Through Ezio's help however, both his mother and younger sister managed to survive, finding a way to escape the city with him. According to the Florentine Guard's record books, Ezio appeared as a womanizer, with guards rarely able to capture him,

From the day of his family's execution, Ezio is labeled a criminal and a traitor. This atrocity leads to Ezio beginning the ways of the Assassins. With the help of a good friend Leonardo da Vinci, Ezio is able to get one of his father's weapons, the Hidden Blade, and uses it to kill Uberto Alberti. Afterward, Ezio flees with his mother and sister out of Florence to Monteriggioni and meet with his uncle Mario, who saves them from an attack from another family, the Pazzi, who was involved in the execution. Mario teaches Ezio how to fight, and soon, Ezio and Mario are able to corner Vieri de' Pazzi and Ezio assassinates him. Soon, Ezio continues his work as an Assassin, killing numerous enemies and helping many factions such as the Thieves, Courtesans, and Mercenaries. But a new enemy named Rodrigo Borgia is discovered by Ezio to be a sworn enemy to his father, Giovanni. Time goes on, with Ezio continuing to bring criminals to justice and his hunt for Borgia continues, in a quest that takes him to several important cities of the Italian Renaissance. But soon, when Ezio finally corners Borgia in Venezia, Mario, Paola (a friendly Courtesan) and many more Assassins help Ezio fight Borgia's men. Antonio of the Thieves faction, surprises Ezio by being an Assassin, and another man, Niccolò Machiavelli is soon discovered to also be one. An ancient ceremony is then conducted, and Ezio is inducted into the ranks of the Assassins and is also revealed to be the Prophet, who will lead them to "the Vault", by bringing together the scattered pieces of the Codex, a sacred book of the order written by Altaïr, containing all the knowledge of the order and all the secrets he gathered from the Apple of Eden.

During the events of Assassin's Creed II: Discovery, which plays during Assassin's Creed II, Ezio travels to Spain in 1490 to free his fellow assassins, who have been imprisoned under the guise of the Spanish Inquisition. In the process, he discovers that the Knights Templar are planning to sail west to discover the New World.[1] Ezio had to save Christopher Columbus and kill Tomás de Torquemada to end the Templar threat. Ezio also had to assassinate some other important targets such as: Gasper Martinez, Pedro Llorente, a Templar spy, and Juan de Marillo. Along the way Ezio saves many assassins who help him, including Luis de Santángel and Raphael Sanchez. Also Granada City is taken under siege by Templars and Ezio has to save the Moorish King Muhammad XII. Ezio also encounters Queen Isabella.

Years later, in 1492, Borgia becomes Pope Alexander VI at Vatican City. By 1499, Ezio and his allies are revealed to have completed the Codex and discover that "the Vault" lies in Rome, with the Papal Cross being another Piece of Eden. Ezio's allies then distract the city while Ezio infiltrates the Vatican. Ezio attempts to assassinate Borgia, but after a long fight, the Pope used his Staff to freeze Ezio, wounding him with a knife, then escaping with both the Staff and the Apple. Ezio used his Eagle Vision to find Borgia and fights him unarmed, easily defeating the older man. Ezio decides to let Borgia live, realizing that vengeance is not so sweet, and it will not bring back his family if he kills him. Now wielding the Staff and Apple, Ezio opens the Vault, in which a holographic figure approaches him, calling herself "Minerva" and identifies him as the Prophet. She explains of others like her who were an advanced society that lived with humans, but both of them went to war. Then, a natural, celestial disaster had occurred, and the surviving humans had rebuilt humanity, and also made several Temples to avoid the disaster from happening again. Minerva then fades after mentioning Desmond Miles, the protagonist of the series viewing the memories of Ezio, that the rest is up to him. Ezio is left confused as he tries to ask who Desmond is.

After returning to his uncle's villa from Rome at the start of Assassin's Creed: Brotherhood, the villa is besieged by the Papal Armies led by Cesare Borgia, son of Pope Rodrigo Borgia and the new de facto leader of the Templar Order. The legendary Apple of Eden is lost, the villa is sacked, Caterina Sforza is kidnapped, and Ezio's uncle Mario is killed in the siege. Escaping outside the city with his mother and sister and the surviving townsfolk, Ezio sets off for Rome to destroy the Borgia Family once and for all. However, Ezio seriously wounded himself in the villa attack; he collapses and falls unconscious on the road to Rome. Days later, Ezio awakens in Rome in the care of good Samaritan. He receives a new set of assassin robes and his basic gear, brought to him by a mysterious man. After healing up, Ezio meets with Machiavelli and sets his plans in motion to liberate Rome and remove the Borgias from power permanently, as well as retrieve the Apple of Eden. Slowly, over the next 3 1/2 years, Ezio and his allies win a series of victories over the Borgias, reclaiming and restoring the city. In 1503, Ezio assassinates Cesare's banker and French general ally, leaving his power base in disarray. Cesare, in a fit of rage, kills his father, the Pope, and begins losing control over the city. By the end of 1503, Borgia control over the city is completely broken and Cesare is arrested by the new Pope. Ezio had also recovered the Apple of Eden and hid it below the Colosseum in the Temple of Juno. Cesare ultimately escapes from prison and heads to Spain to raise a new army. In 1507, Ezio travels to Spain and catches up with Cesare at the siege of Viana Castle. Ultimately defeated by Ezio, an indignant Cesare Borgia is thrown off the castle walls to his death. Ezio then returns to Rome as the leader of the new Brotherhood of Assassins.

After the events of Brotherhood, Ezio discovers a letter from his father that talks about a hidden library full of vast knowledge hidden underneath Masyaf Castle by legendary Assassin Altaïr Ibn La'Ahad, setting the events of Assassin's Creed: Revelations into motion. In 1510, Ezio sets out from Rome to uncover this library and the knowledge it contains. Arriving at Masyaf in early 1511, Ezio is ambushed by Templars who occupy the fortress and are also searching for Altaïr's Library. After escaping capture and assassinating the Templar captain, Ezio recovers the journal of Niccolò Polo, which tells of the five seals hidden in Constantinople which will open the door to Altaïr's library. Arriving in Constantinople, Ezio begins his search for the seals while helping the local Assassin's Guild get rid of Byzantine Templar control. Ezio succeeds in eradicating Templar influence and subjugating the city to the rule of the family of Prince Suleiman. Recovering four of the five keys, Ezio then travels to an underground city in Cappadocia in the year 1512, the new Templar base of operations. After assassinating the Templar leader Manuel Palaiologos and recovering the final key, it is revealed that Prince Suleiman's uncle Prince Ahmet has been secretly leading the Byzantine Templars and wishes to open Altaïr's library for himself. Upon returning to Constantinople, Ezio finds that his love interest Sofia Sartor has been kidnapped by Ahmet to force Ezio to return the keys. Leading an attack with the Constantinople Assassins, Ezio ultimately saves Sofia and recovers the keys from Ahmet. Ezio and Sofia make their way back to Masyaf and open Altaïr's Library, where Ezio finds Altaïr's Apple of Eden and that the entire purpose of the library was to convey a message to Ezio's descendant Desmond Miles.

In the animated short Assassin's Creed: Embers, it is shown that Ezio retired from the Assassin Order and settled down in a Tuscan villa of Monteriggioni with Sofia and had two children, Flavia and Marcello. Years later, a mysterious Chinese woman appears at his door requesting his help. The woman, Shao Jun, is a member of the Chinese Assassin Order and sought Ezio's advice in how to help her people and rebuild their order. After helping Shao fight off soldiers sent by the Chinese Emperor, Ezio sees Shao on her way back to China, armed with the wisdom she came seeking Ezio for. Shortly thereafter, while on a trip to the market square in Florence, a young man approached Ezio, berating the women of Florence. Ezio responded by implying the man was the problem, not the city. Immediately afterward, Ezio began panting and holding his chest in pain. The young man quickly grabbed Ezio's hand and told Ezio to have courage. Breathing heavily, Ezio looked over at Sofia and Flavia, smiling, before passing away peacefully. His legacy and contributions to the Assassin order would continue to resonate for hundreds of years following his death.

His signature outfit can also be unlocked in all subsequent releases of the series. Ezio also appears as a guest character in the fighting game Soulcalibur V. His costume is unlockable in the PlayStation 3 and Xbox 360 versions of Prince of Persia: The Forgotten Sands and Final Fantasy XIII-2, as well as in LittleBigPlanet for the PlayStation 3 and PowerUp Heroes for Kinect on the Xbox 360. His signature hood (under the name the "Dashin' Hashashin") was presented as promotional headgear to Team Fortress 2 players who had pre-ordered Assassin's Creed: Revelations, along with a special knife modeled after his hidden blade (called "The Sharp Dresser") for the Spy class in the game.

The character was critically acclaimed by the media and general public alike. Ezio Auditore received an award from GameSpot for the "Best New Character" in 2009.[2]GameZone had him nominated for "Gaming God of 2009".[3] He was also nomination at the Spike Video Game Awards 2010 for "Best Character" and received an award for the "Best Dressed Assassin".[4] The 2011 Guinness World Records Gamer's Edition lists Ezio as the 35th most popular video game character.[5] Ezio was also voted as the third top character of the 2000s decade by Game Informer '​s readers.[6]

In 2012, GamesRadar ranked him as the seventh "most memorable, influential, and badass" protagonist in games.[7] They also placed him second on the list of most badass game characters of the generation, saying "Ezio has become synonymous with the image of the video game assassin",[8] and declared him the "Mister 2009" in their article on the sexiest new characters of the decade of 2000.[9] Further, GamesRadar placed him at number 4 in a list of the 50 best game characters of the generation.[10]Complex listed Ezio among the "most badass" video game character of all time in 2013, ranking him at 37th place.[11]Complex ranked him as having the tenth best fighting game cameo for his guest appearance in Soulcalibur V in 2012.[12]PlayStation Official Magazine ranked Ezio fifth on their list of "finest facial hair gaming has to offer".[13] He also featured on UGO Networks's list of most memorable Italians in video games at 15th place.[14]